1. Field of the Invention
The present invention relates to a high-voltage light-emitting diode lamp used as a general ornamental sign lamp, a neon sign lamp, and as an indoor illumination lamp.
2. Description of the Prior Art
Conventional light-emitting diode (LED) lamps use either a 12- or 14-V power source and cannot be connected directly to the general AC outlet power source (100 V). As shown in FIG. 6, a conventional LED lamp of this type has a base 2 attached to one end of a glass bulb 1. A printed circuit board 5 is mounted within the glass bulb 1 through a stem 3 and stays 4. A plurality of light-emitting diodes (LEDs) 6 are mounted on the printed circuit board 5. A current is supplied to the LEDs 6 through a series resistor 7. An inert gas such as N.sub.2 gas is sealed in the glass bulb 1.
Since the LED lamp having the above arrangement uses either a 12- or 14-V power source, a low power series resistor 7 can be used and mounted within the glass bulb. However, when a 100-V power source is used, a large, high-power resistor is required, which is quite difficult to incorporate in the glass bulb. For example, when a series resistor is provided immediately under the printed circuit board, heat generated by the resistor degrades the characteristics of the LEDs. In addition, since a 100-V LED circuit is formed within a single glass bulb, the size, shape and number of the means for mounting the series resistor are restricted.